Grate



0a. 6, 1942. KWOLEK 2,297,783

GRATE Filed Oct. 13, 1939 2 Sheets-Sheet l STEPHEN 5. KWOLEK' HIS AT7OENE r INV ENT OR.

Oct. 6, 1942. 's. s. KWOLEK GRATE Filed Oct. 13, 1939 2 Sheets-Sheet 2INVENTOR.

mm N NM m o w w N k e s. m

-T m A p s M H 5 w Patented Oct. 6, 1942 UNITED STATEE E ATENT OFFICEGRATE Stephen S. Kwo'lek, Detroit, Mich.

Application October 13,1939, Serial No. 299,312

6 Claims.

My invention relates to a new and useful improvement in a grate adaptedfor use on furnaces and the like with which combustible fuel such ascoal or the like is used. A type of grate construction embodying asupporting body or plate through which openings are formed leading tothe air chamber or ash pit positioned below the grate. With this type ofgrate the space below the grate ordinarily is not used as an ash pitbecause of the substantially complete combustion which is obtained bythis method of combustion. The ashes ordinarily are raked or hoe-d ofiof the grate directly into a wheelbarrow positioned at the front of thefurnace. This operation takes the place of the operation in whichdump-grates are used, in the use of which the ashes are dumped into apit and then removed therefrom.

The space below the grate is used as an air chamber in which air isbuilt up under pressure and maintained under pressure for effecting aconstant blowing of air upwardly through the openings in the grate, thefuel being deposited upon the upper surface of the grate. Experience hasshown that with this type of grate, warping and cracking of the mainplate often takes place and in some instances pieces of the plate breakoff and fall downwardly into the chamber below.

It is an object of the present invention to provide a grate of this typearranged from a plurality of sections having each section so constructedthat a maximum strength is provided and the adjacent sections serve assupporters for each other so that warping and cracking is reduced to aminimum and the dropping of a cracked-air piece into the chamber belowthe grate is prevented.

Another object of the invention is the provision of a grate of this typewhich will be simple in structure, economical of manufacture, durable,easily and quickly assembled and disassembled and highly efiicient inuse.

Another object of the invention is the provision of a grate of this typewhich will he possessed of a minimum of weight and a maximum of strengthproportionately to the weight.

Another object of the present invention is the provision of a grate ofthis type so constructed as to present a maximum surface to the coolingair projected through the grate so as to maintain the grate cooled to amaximum degree.

Another object of the invention is the provision of a grate of this typeso constructed and arranged as to possess uniform weight and time,presenting a maximum area for combustion purposes.

Another object of the present invention is the provision of a gratehaving openings formed therethrough arranged in sets of a centralvertical opening surrounded by a plurality of angular passages oropenings with adjacent sets rotated relatively to each other preferably45 degrees to provide uniformity of spacing and distribution so that auniform air surface throughout the entire grate area may be obtained.

Another object of the present invention is the provision of a grate inwhich dead air pockets are eliminated.

Another object of the present invention is the provision of a grate inwhich a maximum elliciency in operation is obtained.

Another object of the present invention is the provision of a gratecomprising a plurality of sections having portions interlocking witheach other.

Other objects will appear hereinafter.

In the drawings I have illustrated the preferred forms of constructionbut it is recognized that various changes and modifications may be madewhich would be a departure from the precise detail of structure shownbut still embody the essential features of the invention,

and it is intended that such variations and strength throughout its areawhile, at the same 55 modifications shall be included in thisspecification. The specification is amplified with drawings, in which,

Fig. 1 is a longitudinal sectional view of a furnace embodying theinvention with parts broken away,

Fig. 2 is a transverse sectional view or" the invention with partsremoved, Figure 2a is a top view of a segment of the connection betweenabutting sections,

Fig. 3 is a top plan View of the invention with parts broken away,

Fig. 4 is a sectional view taken on line 44 of Fig. 3,

Fig. 5 is a bottom plan view of a slightly modified form of theinvention with parts broken away,

Fig. 6 is a top plan View of a fragment of the invention slightlyenlarged over Fig. 5,

Fig. 7 is a fragmentary sectional view taken on line l-1 of Fig. 6,

Fig. 8 is a prospective view of one of the units used in the invention.

In the drawings, I have illustrated the invention used with a furnacehaving a rear bridge wall 9 and a front wall Ill provided with anopening il giving access to the air chamber l2 below the location of thegrate. Supported by the wall or stoker front IE3, is a supportingbracket or hearth plate l3 attached to which, by means of the clampplates l4 and the bolts I5, is one end l6 of a grate section. Theopposite end ll of the grate is secured by U-shaped clips is to theadjacent end [9 of another section which is supported at its oppositeend by the ledge 23 on the wall 9. Stay bolts 2! are projected throughthe end walls of these grate sections. These grate sections are adaptedfor being positioned in juxtaposition to other sections to form acomplete grate. It will be noted that each section is provided with itsown stay-bolts so that these staybolts do not serve as a means forbinding the separate sections together.

As shown in Fig. 8, the section is of box-like structure embodyingoppositely disposed side walls 22 and end walls 16 and I? so that asubstantially box-like structure is provided, the bottom thereofcomprising the plate 24 which forms the grate proper. Transverselyextending fins in the form of plates 25, project inwardly from the innersurface of the box 24 as do, likewise, longitudinally extending fins 25.These fins project downwardly when the grate is in operative position,the box-like structure being mounted with the open end faced downwardly.It will be noted that in each of the sections the stay-bolts extendbelow and are substantially tangent to the downwardly projecting finmembers. Each set of sections 25 and 2t defines an area on the base orbottom 2 and through the base or bottom Ed at each area is formed acentrally positioned opening 2'! which is tapered as clearly shown inFig. '7, the narrow end thereof opening through the upper face 28 of thebottom 2 Extending through this same area is a plurality of diagonallydirected or inclined passages 29 which are also tapered. These passagesserve as outlets for air which may be delivered into the chamber 12under pressure. It will be noted that the inclined passages are arrangedaround the central vertical passage 21 and as shown in Fig. 6 thearrangement is such that openings in adjacent sections are rotated 45degrees so that a uniform distribution of air outlets over the entireface of the plate 2 3 is obtained. The fins 25 and 26 form with eachother on the inner surface of the bottom 24, separate box-likestructures and the air forced through the passages 2? and 29 entersthese box-like structures and has a cooling effect on the grate.

As shown in Fig. 1 and Fig. 2, there are no dead air pockets and thereis no dead weight of the grate at its opposite ends so that the maximumarea of useable surface is thus provided.

Experience has shown that when a grate is constructed in this manner, amaximum efficiency is obtained. The air, before passing through theoutlets 27 and 29, becomes preheated, so that the cooling effect of theair on the combusted fuel is reduced to a minimum. The grate ismaintained at a fairly cool condition and, no blow holes in the fuel bedare effected, while clinker formation under proper air regulation ispractically eliminated, regardless of the grade of fuel used.

It is intended that the grate shall be used primarily for burning solidfuel and it is adapted for burning coal and other fuels from lump sizesdown to dust and the grate may be used with either a natural or forceddraft pocket in con- The grate is also suitable for use in furnaces ofthe hand-fired type and experience has shown that it is quite welladapted for use on marine boiler of the land type and the Scotch marinetype.

In assembling the grate, the various sections are abutted side to side.Each of these sections is provided on one side with a U-shapedlongitudinally directed groove 3| and on the opposite side with agripping rib 32, the rib of one section engaging in the groove of theother. At intervals, these structures are provided with the openings 33.The openings 33 of abutting sections would register so that a U-shapedconnecting clip 34 may be inserted through the openings as shown in Fig.2 to pin the sections together. In the groove 3! I prefer to pack alayer 35 of asbestos or other suitable packing so that there is no openspace exposed on the upper face of the grate. It is also to be notedthat there are no ribs or projections extending upwardly from the face28 of the grate body.

Engaging at the upper edges in the space 36 between the abutting wallsis a partition plate 3! which serves to partition the chamber i2 and thesections to assure proper distribution of the blast air to the entiregrate structure. This permits cutting the grate into sections or permitsthe Zoning so that certain sections of the grate may be cut out of usewhen light loads are encountered.

In Fig. 1, I have illustrated a supporting I- beam 38 but the use ofthis I-beam is optional.

What I claim as new is:

1. A grate section comprising a unitary boxlike structure having a top,end walls, and side walls and a plurality of spaced transverselyextending and spaced longitudinally extending partitions projectinginwardly from the inner surface to the top, said partitions extending atright angles to each other and said transverse partitions extending atright angles to the longitudinal edges of said structure; and aplurality of bolts extended through and connecting oppositely disposedend walls.

2. A grate construction of the class described comprising a plurality ofbox-like sections having oppositely disposed side walls, the side wallsof adjacent sections being in substantially abutting relation, each ofsaid sections having an opening formed therethrough on the inner side ofthe side wall and provided on its upper face with a groove communicatingwith said opening; and an inverted U clip projected through saidopenings and having the bight thereof lying in said groove forconnecting said sections together.

3. In a grate construction of the class described, a plurality ofbox-like structures arranged in abutting relation with the side wallssubstantially in engagement, each of said sections having an openingformed therethrough adjacent the inner surface of the side wall; andinverted U clips projected through said openings for connecting saidsections together.

4. A grate section of the class described comprising: a box-likestructure having a pair of oppositely disposed side walls and a pair ofoppositely disposed end walls and a top, the remaining side of saidstructure being open; a plurality of transversely extending partitionsbetween said side walls and extending inwardly of said top; a pluralityof longitudinally extending junction with overfed sprinkler typestokers.

partitions between said. walls and extending at right angles to saidtransversely extending partitions; and stay-bolts projected through apair of from said top and extending at right angles to said end walls; aplurality of transversely extending partitions extending inwardly fromsaid top at right angles to said side walls, said partitions being ofless height than said oppositely disposed walls; stay-bolts projectedthrough said oppositely disposed walls and positioned substantiallytangent to the inner edges of said partitions.

6. A grate section of the class described, comprising: a box-likestructure having a pair of oppositely disposed end walls, a pair ofoppositely disposed side walls and a top; a plurality of intersectingpartitions projecting inwardly from the inner side of said top, saidpartitions being of less height than said walls for providing, in saidstructure, a plurality of separate compartments; and stay-boltsprojected through a pair of oppositely disposed walls and substantiallytangent to the inner edges of said partitions.

STEPHEN S. KWOLEK.

